In the past, self-propelled utility vehicles, such as scissor lifts and other equipment have had limited steering capability, which reduced their usefulness to the user. Typically, a four-wheel scissor lift vehicle has two fixed wheels and two steerable wheels, but the steerable wheels have a limited range of steering. With such an arrangement, it is difficult to steer the vehicle to the desired position. For example, when using a scissor lift next to a wall so that the platform being supported by the scissor lift can be positioned immediately adjacent and parallel to the wall, a large area is required for maneuvering. This is so the vehicle can be moved back and forth until it is in the desired position. Unfortunately, adequate area is not always provided, such as when working within buildings where obstructions and limited space prevent the required back-and-forth movement of the vehicle, or make the process of maneuvering the vehicle so slow and difficult that the user cannot take the time or the risk involved to properly position the vehicle. The longer the vehicle, the worse the situation becomes.
It will therefore be appreciated that there has long been a significant need for a utility vehicle with improved steering which increases the maneuverability of the vehicle. Preferably, the steering system will allow the steerable wheels a total steering range of at least 180.degree., with 90.degree. steering to each side of a center position. With such an arrangement, one end of the utility vehicle can be positioned adjacent the wall and the steerable wheels turned 90.degree. to cause the other end of the utility vehicle to move directly toward the wall. This would allow a quick and easy positioning of the utility vehicle in the desired position adjacent and parallel to the wall. If desired, the steering system should allow the forward wheels and the rearward wheels to be separately steered for increased maneuverability. The steering system must not only provide a sufficient steering range, but must also produce sufficient torque to turn the steerable wheels when the vehicle is fully loaded. The present invention fulfills these needs and further provides other related advantages.